A semester is an academic term lasting approximately half the school year, typically 4-5 months. Many Canadian secondary schools and most post-secondary institutions use semester systems, with fall and winter semesters being most common. Under semesterized systems, students typically take fewer courses at a time but complete them within the semester, rather than taking more courses over a full year. Some schools use trimesters (three terms) or quarters (four terms) instead. The semester structure affects course scheduling, exam periods, and grade reporting. Students may have different courses each semester, allowing for varied schedules and completion of prerequisites before advancing.